PURPOSE:To contrive to improve color separation, ground fogging, head matching property or the like, by a method wherein a base with a filler-containing polymer resin layer provided on its surface is used, and an intermediate layer of a water-soluble polymer is provided between a plurality of heat-sensitive color forming layers laminated on the base. CONSTITUTION:A polymer resin layer containing an inorganic or organic filler such as silica, magnesia or aluminum stearate is provided on the surface of an ordinary base in an amount of 0.5-10g/m . An emulsion-type alkyd resin, a styrene/butadiene copolymer or the like may be used as a polymer resin. A low- temperature color forming layer comprising a leuco dye and a color developer as main constituents and a high-temperature color forming layer are laminated on the base, in which case the intermediate layer comprising a water-soluble polymer such as polyvinyl alcohol or methoxy cellulose is provided between the upper layer and the lower layer, in the amount of 0.5-7g/m in an usual case.